[palata]

When you connect to a WiFi network, the goal is to be part of the network. Which means that all the devices on the network can reach each other.

If you have a password, it means that you select who can be part of that network (and hence who can reach your computer). If you don't have a password (e.g. a guest network somewhere), then there is no selection at all.

Now, if you let anyone connect and have a "fake" password, you still don't have any filter and should know that you are on a "public" network (i.e. you should not blindly trust other devices). So it's actually better to be able to see that you are on a "public" network (versus a "trusted" network like your home LAN).

Or did I misunderstand your question?